The overall goal of the Clinical Core is to generate data and biospecimens required to support high quality, cutting edge, externally-funded clinical and clinical-pathologic studies that focus on the full spectrum of cognition from normal aging to mild cognitive impairment (MCI) to the earliest stages of dementia among older African Americans. Historically, progress in Alzheimer's disease (AD) research has been most striking among members of the U.S. non-Hispanic white population. However, because of the expected increase in the growth of the older African American population, because African Americans may be at greater risk of AD than whites, and the burden of AD and mixed dementias is projected to increase dramatically for this population, the Rush Clinical Core will focus on enrolling and following African Americans longitudinally to accomplish the following Specific Aims: 1) Continue to recruit and enroll African Americans without dementia who agree to annual, detailed clinical evaluations and collection of ante-mortem biologic specimens;2) Continue to conduct uniform structured baseline and annual follow-up evaluations, including neurological examination and neuropsychological performance testing, of community-dwelling Clincal Core participants, apply uniform diagnostic criteria for incident AD, MCI, and mixed dementias as specified in the UDS, and supplement UDS data collection with an extended battery of tests to increase compatibility with the Religious Orders Studies Core;3) Integrate innovative and culturally tailored educational programs into the clinical evaluation to increase awareness of the importance of brain autopsy in African Americans and to facilitate a high autopsy rate with a short post-mortem interval;and continue to harvest and preserve the brain tissue in a fashion that retains maximum flexibility to support a diverse array of studies;and 4) Increase capacity to conduct externally funded clinical, neuropsychological, and clinical-pathological research studies, including studies that incorporate contemporary biochemical and molecular techniques, by contributing data to NACC and providing an environment and resources to facilitate entry of subjects, clinical data, and post-mortem tissue into research projects at Rush and within the AD research community at large.